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Research

ABC Lab Research

The ABC Labs’s research focuses on understanding the neural mechanisms underlying visual perception and cognition in healthy and clinical populations. The lab is using approaches of psychophysics and cognitive neuroscience, such as functional magnetic resonance imaging (fMRI), and event-related potentials (ERPs). The current projects include developing neurosignatures of memory malfunction and cognitive impairment due to aging or brain damage, and measuring individual differences in behavior, brain responses and genetics associated with cognitive and affective processes.

Current Research Projects and Sample Publications

1. Neuroimaging Indicators for Cognitive Impairment

Brain mechanisms such as changes in synaptic connectivity underlying alterations in cognition are detectable before behavioral measures of cognition and clinical diagnosis. In the past decade, the Aging Brain and Cognition laboratory (ABC lab) has developed reliable fMRI connectivity [a] and electrophysiological biomarkers (network EEG [b] or cognitive ERP [e]) measured during resting or visual cognition tasks. These biomarkers allow for the differentiation between cognitively normal adults. They can also be used to distinguish patients with AD or MCI from cognitively normal older adults [c]. The same techniques have also been employed to identify subjects with TBI [d] and malingered neurocognitive deficit. At present, these methods are being used in research to characterize patients with Posttraumatic Stress Disorder (PTSD) and cancer patients treated with chemotherapy.

We have advanced the understanding of brain mechanisms involved in two types of short-term memory in humans, explicit working memory and implicit repetition learning memory. Jiang et al. (2000) used fMRI to characterize and first report the existence of these two complementary forms of memory [2d]. After the ABC laboratory was established at the University of Kentucky, we extended this study and reported new evidence on the temporal dynamics of the neural mechanisms underlying working memory [2a] and repetition learning [2c]. We also identified that during cognitive aging, brain responses are altered during working memory retrieval, even though memory accuracy remains high [2b]. Please see a review on cognitive performance and neuroimaging and genetic approaches in [2e].

How the brain processes visual luminance, motion, depth, 3D object shape defined by movement [e] in different parts of visual cortex, and combines this information into a coherent perception of a rotating 3D object is still not completely understood. By conducting experiments using visual psychophysics, fMRI imaging, magnetoencephalography (MEG), and EEG imaging approaches, my results support the idea that combining different visual information on a single object in a 3D space occurs through synchronized oscillating brain activity in different brain regions [b]. Using simultaneous fMRI and eye-tracking recordings, we identified distinct brain networks underlying motion perception and visual memory [a,b,c]. These findings have shown promising clinical application for assessing brain injury recovery of athletes after sports injuries [d].

4. Individual Differences in Neural Mechanisms of Personality, Affect, and Risky Social Decision-making

In recent years, the ABC lab has investigated how individual differences in genetics and personality modulate behavior and underlying brain responses, e.g. lower-functioning dopaminergic activity (e.g. dopamine D2 receptor) puts individuals at risk for violence because it motivates them to experience aggression's rewarding qualities [a]. We report new findings that sensation seeking, boredom, or math anxiety modulate brain responses in affective processing[c], decision-making [d], repeated perceptual experience [e], and cognitive task performance [b]. Much of this work was initiated by students and collaborators and it has significantly broadened our research horizon.